This application aims to foster the career development of a diverse and exceptionally well trained group of pediatric endocrinologists entering the field of pediatric diabetes research through a joint institutional career development program at Boston Children's Hospital and the Joslin Diabetes Center. Through mentored training of pediatric endocrine scholars who have completed fellowships in pediatric endocrinology, this joint program will support and nurture career development of junior faculty in biomedical and behavioral diabetes investigations relevant to pediatric diabetes. Based upon the longstanding history of collaboration between Children's and Joslin, our extensive diabetes research programs, and our record of successful career development of pediatric endocrinologists becoming independent diabetes researchers with support over the last 10 years from our K12 career development program for pediatric diabetologists, we aim to mentor a new group of pediatric endocrinologists who will become future leaders of pediatric diabetes programs in the United States. Each year we will provide career development and support for up to 3 years for 3 recent graduates of pediatric endocrinology fellowship programs. Children's and Joslin are ideally suited for this institutional career development award due to our extensive group of faculty mentors, multi-disciplinary training programs, commitment to mentoring predoctoral students, post-doctoral fellows, and junior faculty in research relevant to diabetes, and our available pool of diverse, talented candidates for appointment to the K12 program. The rationale for the application includes: the increased occurrence of both type 1 and type 2 diabetes in childhood, the need to discover the root causes of type 1 and type 2 diabetes, the challenges of achieving optimal glycemic control in youth, the high risk of short- and long-term diabetes complications, the outstanding diabetes research at both institutions, the need for research to increase our understanding of uncommon genetic forms of diabetes, the demands of implementing and maintaining intensive insulin therapy and new monitoring technologies in children, opportunities with automated insulin delivery, and the need for trained and committed pediatric diabetes investigators to advance research aimed at treating, preventing and curing these disorders. Given the history of diabetes research at our institutions and the richness of the Harvard Medical School environment, this joint application offers a unique setting for career development of pediatric endocrinologists committed to careers in pediatric diabetes. Co-Principal Investigator and Program Director Lori Laffel MD MPH and Co-Principal Investigator Morris White PhD, supported by an Advisory Committee, are in optimal positions to orchestrate this endeavor. Career development is enhanced by Joslin's NIH-supported Diabetes Research Center (DRC), Harvard's CTSU, and Harvard's Catalyst Program. We have consistently demonstrated the ability to attract highly qualified candidates to our training programs and look forward to meeting the challenge of nurturing the careers of pediatric endocrinologists as pediatric diabetes investigators.